Which AVA has a wider diurnal temperature range?

The diurnal temperature range refers to the difference between daytime highs and nighttime lows within a given area. A wider diurnal temperature range is often favorable for grape growing because it allows the grapes to develop complex flavors and acidity during the cooler nighttime temperatures, while ripening occurs during the warmer daytime hours.

Calistoga, located in Napa Valley, is known for its geographical features that contribute to a significant diurnal temperature variation. The region is situated in a valley where it can experience warm daytime temperatures due to its location, but as the sun sets, the temperatures can drop considerably, especially in the evenings. This variation is influenced by the surrounding mountains and the way they affect airflow and temperature moderation.

In contrast, regions like Mendocino, Sonoma Valley, and Russian River Valley may not experience as pronounced a difference between day and night temperatures, due to their proximity to larger bodies of water like the Pacific Ocean, which provide a moderating effect on temperature. This can result in a more consistent climate without the significant temperature swings that characterize Calistoga.

Therefore, the choice of Calistoga reflects its unique microclimate that supports a greater diurnal temperature range, making it ideal for certain grape varietals and contributing to the overall quality of the wine produced